Corporate regulator ASIC has been asked to consider action against the insurer based on the evidence of Glenn Sutton, whose Airlie Beach home was further damaged after repairs were delayed and he was not reimbursed for temporary accommodation after the 2017 disaster.

Similar poor treatment of another Youi policyholder, Sacha Murphy, over her claim for hail damage to her Broken Hill home was also singled out in the referral to ASIC.

In evidence to the Royal Commission, Mr Sutton detailed how the builder selected by Youi to repair his roof was allocated eight hours to complete the work, did not install a tarpaulin and did not conduct any drying work to prevent mould.

"Once we had a bit of wind, the tarpaulin was torn to shreds and water was pouring back into the building," Mr Sutton said in his testimony.

He and his wife were hit with further delays and forced to move temporary accommodation multiple times while his case manager, based in South Africa, was difficult to contact.

In a scathing finding, Commissioner Kenneth Hayne said Youi's actions were unprofessional and may have amounted to misconduct.

While he could not pass an opinion on the treatment of other Cyclone Debbie victims, Commissioner Hayne said Youi's actions had exacerbated damage to Mr Sutton's property and placed him under financial strain.

"(At) least in relation to its handling of Mr Sutton's claim, Youi failed to respond to that catastrophe in a way that was efficient, professional, practical and compassionate," Commissioner Hayne said.

Youi's Chief Operating Officer Jason Storey conceded in evidence to the Royal Commission that the insurer did not have appropriate processes in place for the repairs and was responsible for delays that created hardship for Mr Sutton.

After his evidence, Youi complained the Royal Commission's counsel assisting Rowena Orr had presenting Mr Sutton's case in the worst possible light and did not prove there was a culture of wrongdoing at the insurer.

But Commissioner Hayne dismissed this complaint, saying Youi's lawyers did not cross examine Mr Sutton or refute his claims. "Youi had ample opportunity to contextualise or draw the Commission's attention to whatever matters it chose," Commissioner Hayne said.